Combustion synthesis assisted water atomization-solid solution precipitation: A new guidance for nano-ZTA ceramics

It is difficult to synthesize ceramics with ultra-fine nanostructures because of inevitable grain growth during the sintering process. In this work, a novel technique, i.e. combustion synthesis assisted water atomization (CSAWA) method, was invented to synthesize supersaturated Al₂O₃/ZrO₂ solid solution powders. The huge cooling rate supplied by CSAWA greatly improved the solubility of Al³⁺ in ZrO₂ lattice. Subsequently, the synthesized powders underwent a solid solution precipitation process. The ultra-fine ZrO₂ nanoparticles and Al₂O₃ matrix are precipitated from metastable phase, and the ZrO₂ nanoparticles are uniformly dispersed in Al₂O₃ matrix. Simultaneously, the powders were densified and formed compact ZTA ceramics. Together with detailed microstructure, phase composition, interface characteristic, mechanical properties, as well as the toughening mechanisms were collaboratively outlined. CSAWA-SSPP not only produces impressive comprehensive properties, but also much lower costs and simpler process than currently methods, which opens up a new route to industrially produce nano-ZTA ceramics with high performance.